Drop bottom car



R. A. SHIELDS DROP BOTTOM CAR Feb. 16, 1954 3 Sheets-Sheet l Filed Jan. 16, 1951 .lnrndhlllll lnnlllnfluinillillklllll;

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Feb. 16, 1954 R. A. s'Hu-:Lns

DROP BOTTOM CAR 3 Sheets-Sheet 2 Filed Jan.' 15,*1951 v INVENTOR Illllllll R. A. SHIELDS.

DROP BOTTOM CAR Feb.'16, 1954 5 Sheets-Sheet 5 Filed Jan. 16, '1,951

Patented Feb. 16, 1954 DROP BOTTOM CAR Robert A. Shields, Bloomsburg, Pa.. assig'nor to American Car and Foundry Company, New York, N. Y., a corporation of New Jersey Application January 16, 1951, Serial No. 206,145

14 Claims.

This invention relates to mine cars in general and in particular to drop bottom cars in which the doors are mounted to swing longitudinally of the car to discharge the lading.

Drop bottom cars as now constructed have the doors mounted to swing about fixed axes or about a single oscillating axis. The majority of drop bottom cars have the door interrelated and controlled by single latch means and all openl from the rear to the front of the car, however, some types of hinging means permit the doors to be conditioned for opening upon a very slight drop, and these cars may operate to discharge into thc bin from the front toward the rear. Normally, this latter type of cars is known as l-2-3 drop cars as distinguished from the more conventional 3-2-I sequence of dumping. Certain linkages for l-2-3 type of dump do not permit suicient overlap between doors to prevent accidental discharge, and others require too great a drop before releasing the next forward door. It is an object, therefore, of the present invention to provide a drop bottom car having door control linkages giving large horizontal movements at the forward edge of the door with but slight opening of the door.

A further object of the invention is the provision of a drop bottom car having improved door control linkage permitting large overlap between the adjacent doors.

A still further object of the invention is the provision of a drop bottom mine car having the door movements controlled by pairs of hinge linkages.

Yet another object of the invention is the provision of a drop bottom mine car having door control linkages so arranged as to give a definite 4load dischargesnap to the opening door to therelthe* normalv hanging position.

lFig. .5 isla partial sectional view with parts removed but showing the doors in a partially `opened position prior to discharge` into the bin.

Fig. 6 is an enlarged sectional view showing two positions of a door.

Fig. 7 is an enlarged sectional view similar to Fig. 6 but showing three additional positions of the door, and

Fig. 8 is a plan view of a portion of the door and sill showing the hinge linkage.

Referring now to the drawings in detail, it will be seen that the mine car is fully disclosed in Fig. l and Fig. 2 with the cars supported on wheels W carrying axles l!) which in turn support spaced side sills l2 preferably of angular cross-section and having portions of their top edges inclined outwardly and upwardly as at I4. These portions are attached to inclined portions of the sloping side walls I6 terminating in upwardly directed side walls I8. The side walls I6 and I 8 are connected together by end walls 20 while the ends of the side sills are connected together by end structures 22. Each of the end structures is provided with a coupling pin 24 and one carries a forward bumper F and the other rearward bumper R as clearly shown in Figs. 2 and 1 respectively. Suitable wheel hoods 26 prevent lading being discharged onto the wheels while the side and end walls are suitably braced in any well-known manner by braces 28. The car is suitably braced intermediate the end walls by axle hoods and cross braces 32 suitably attached to each other and to the sills and side walls.

The opening between the side sills and end structures is closed by a plurality of doors 33, 34, and which doors are adapted to close the space and retain lading in the car. The forward door 33 is hinged adjacent the forward end structure upon a iixed axis 36. The intermediate and rear doors 34 and 35 are hinged at each side on a pair of swinging linkages later to be described and which linkages permit large horizontal movement toward the rear of the car during the first few degrees of door opening. The rear door 35 is held in closed position by means of a latch structure 38 engaging a door lug 39 as is clearly indicated in Figs. l and 5.

Each door is preferably made of identical construction so as to decrease the cost of manufacture; and, as shown, each door is formed with a forward rolled edge 40 from which a horizontal portion 42 extends rearwardly merging into `a downwardly inclined portion 44. This downwardly inclined portion merges into a relatively large fiat portion 46 extending rearwardly and slightly downwardly to its point of mergance with an upwardly and rearwardly inclined end portion 48 terminating in an outwardly directed rear lip 5o. This rearwardly directed lip is adapted to rest upon the forward edge of the next rearwardly disposed door when the doors are in closed position. Side plates 52 are welded or otherwise secured to the side edges of the door plates and these extend continuously from the free edge of the door to portions of the slope M. As clearly shown in Fig. 8, the side reinforcement 2 is jogged inwardly and connected by a transversely extending plate 54 to a longitudinally extending plate El disposed beneath the horizontal portion d2 to thereby stiffen the front edge adjacent the hinging rods.

The doors 34 and 35 are as previously stated hinged at each side on a pair of reversing linkages. As clearly shown, a rod to extends through the roll lll and has its ends connected to links A,

which in their normal position extend upwardly and slightly rearward to a pivot connection 62 on the side sills. Rearwardl-y of rod 69 is a rod 6d mounted on the doors by means of straps 66. The ends of these rods are fastened to links B which are connected to short trnnnions 't8 mounted for pivotal movement in strap hangers T0 riveted or otherwise secured to the bottom surface of the side sills. When the doors are in the closed position as shown in Figs. 1 and 2 links A incline downwardly and slightly forward of their pivotal mount while links B incline upwardly and rearwardly from the point of pivotal support on the sill. The degree of inclination of' links A and B can, of course, be slightly changed to obtain a greater or lesser degree of horizontal movement, but as shown links A incline six degrees and links B twelve degrees. with respect to the vertical, and it has been found that such inclination gives very satisfactory door movements.

For purpose of describing the operation, the doors shown in Figs. l and 2A will be referred to as in the No. l position; those in Fig. 5 as in the No. Z position; the line and dash position of Fig. 6 will be referred to as in the No. 3v position; while the full line will be referredto as in the No. 6 position. In Fig. 'l' the linev and single dash will be No. e position; the full line, No'. 5 position; and the line and double dash will be No. '7 position. The operation of the doors will bey as follows assuming them to bein the closed or No. l position. Upon release of the latch structure Sil, the rear edge of door will tend to drop and move the inclined links B and A, forcing the door during its dropping to move a considerable amount horizontally thus freeing door 3,11, which in turn will move horizontally freeing door 35i` and provided no skid plate supports the doors they will swing to full open position. During this, opening the doors will move from position 2 to position 3. As the door linkage moves from the position l to the No. 3 position, links A will be moving in a clockwise direction While links B will have been moving in a counter-clockwise direction. When the links have reached the No. 1i` position indicated in Fig. 6, links A will continue. in a clockwise direction but links B will reverse their direction of moving and start moving in a clockwise direction, thus permitting the door to move from the No. 3 to the No. 4 position. At this time, links A will have reached the limit of their clockwise movement and will start moving in a counterclockwise direction permitting the door to move to the No. 5 position which is the full open position as shown, in. `lig.. 7. With the door moving fromNo. 4 through No. 5; position. it. will he seen that the weight of the door is more. or less unsupported and the door will snap downwardly and terminate in a rearwardly directed whipping action due to the fact that links A reached their fully extended position as shown in full line of Fig. 6. At this time, the links B will have reached the limit of their clockwise movement and when the door is being moved in a closing direction from position 6 to position 7, links B will reverse their motion and start moving in a counter-clockwise direction to the No. 'I position at which time links A will reverse their counter-clockwise motion and start moving in a clockwise direction until the door has moved to the closed or No. l position.

From the preceding, it is seen that links B will oscillate from their terminal positions otherwise the No. 3 and No. 6 positions as shown in Fig. 6. The links* A, will oscillate from their terminal positions; namely, the No. 4 and No. 7 positions shown in Fig. '7. As the doors move downwardly to the No. 3 position in opening, there will be a slight momentary check at the time links B reverse their direction of motion; and, if desired, suitable checks canbe provided limiting the doors to this degree of opening which, in the present case, is roughly thirty-two degrees. However, it is preferred that the doors complete. their motion of opening in which case the drop and rearward snap of the doors will be obtained which will clear they doors` of any material that may have lodged the sloping portion d3.. With the linkages shown, the total door opening movement is roughly 198 degrees. while thev oscillating movement of links A and B lies between 200 and 205 degrees total.

It will be seen that both links A and links B act in compression to support the load on the doors when the doors are in the fully closed' position. In this closed position, the links B may be said to be the main supporting means while links A may be said to act as controlling links helping to resist rotation of the door around the rod 64. As the door moves from the closed to the open positin, links A continue to serve as means controlling the door movements about either rod B6 or the pivotal mount 68 of links B, and it is this interrelation and control function of links A that give the rearward snap to the door as it moves from position 5 to position 6 which will be the normal stable open position of the doors after they have stopped swinging. It is to be noted that any swinging movement of the open door will be resisted by the fact that the door has to be lifted for any motion to occur after it has reached the No. 6 position. In other words, the swinging motion will be, rapidly damped by the weight of the door itself.

It will be obvious that various modifications and rearrangements of parts both in dimensions and angular relation may be made without departing from the scope of the invention as defined by the following claims:

What is claimed is:

l. In a drop bottom can, the combination of a bottom door normally closed to retain lading in the car and swingable to an open position for discharge of lading, a pair of hinge rods extending transversely of the car and about which said door may swing between closed and open positions, and a pair of strut means connected to each hinge rod and pivotally mounted on the car adjacent the ends of the hinge rods, one pair of said strut means. beingv pivoted on the car below the door and the other1 being pivoted on the car above the door.

2. In a drop bottom car, the combination of a bottom door normally closed to retain lading in the car and swingable to an open position for discharge of lading, a pair of Alinks located adjacent each side edge of the door at one end thereof, one link of each pair being pivoted to the car above the plane of the door and the other link being pivoted to the car below the plane of the door, and means pivotally connecting said links to said door.

4. The structure of claim 3 characterized in that the links pivoted to the car below the plane of the door are located between the free edge of the door and those links pivoted to the car above the plane of the door.

5. In a drop bottom car, the combination of a bottom door normally closed to retain lading in the car and swingable about a constrained end to an open position for discharge of lading, a iirst rod carried by the door adjacent the constrained end thereof, first links connected to said rod and 5 pivotally mounted on said car above the plane of the door, a second rod carried by the door in spaced relation to said rst rod, and second links connected to said second rod and pivotally mounted on said car below the plane of the door. 6. In a drop bottom car, the combination of a.

bottom door normally closed to retain lading in the car and swingable about a constrained end to an open position for discharge of lading, a rst rod carried by the door adjacent the constrained end thereof, first links connected to said rod and pivotally mounted on said car above the plane of the door, a second rod carried by the door in spaced relation to said rst rod, and second links connected to said second rod and pivotally mounted on said car below the plane of the door, said rods and pivotal mounting of said. links being so spaced as to give a downward and rearward snap to the opening door whereby lading will be cleared therefrom.

'7. In a drop bottom car, the combination of a bottom door normally closed to retain lading in the car and swingable about a constrained end to an open position for discharge of lading, links pivotally connected to said door intermediate the ends thereof, means pivotally mounting said links on said car beneath the plane of the door, and means pivotally connected to said car and to said door adjacent the constrained end to control together with said links the movements of said door during opening and closing, said last named means comprising a pair of links having their pivotal connection to the car located substantially vertically above their pivotal connection to the door.

8. In a drop bottom mine car, a body having side sills supported by axles located between the upper and lower edges of the sills, a pair of drop bottom doors swingable longitudinally of the car between the sills, links pivotally connected to each door adjacent the side edge and inwardly from one end thereof, means pivotally mounting said links on said sills adjacent the lower edge and beneath the plane of the doors, and means pivotally connected above the plane of the doors (iii 6 to the sills and to the doors adjacent an end thereof to control together with said links the movements of the doors during opening and closing.

9. In a drop bottom mine car, a body having side sills supported by axles located between the upper and lower edges of the sills, a pair of drop bottom doors swingable longitudinally of the car'between the sills, links pivotally connected to each door adjacent the side edge and inwardly from one end thereof, means pivotally mounting said links on said sills adjacent the lower edge and beneath the plane of the doors, and means pivotally connected to the sills and to the doors adjacent an end thereof to control together with said links the movements of the doors during opening and closing, said last named means being pivotally connected to the sills substantially in the plane of the axles.

10. In a drop bottom mine car, a body having side sills supported by axles located between the upper and lower edges of the sills, a pair of drop bottom doors swingable longitudinally of the car between the sills, links pivotally connected to each door adjacent the side edges and one end thereof, certain of said links being pivoted to the sills adjacent the lower edge thereof and others to the sills at points spaced upwardly from the lower edge.

11. In a drop bottom mine car, a body having side sills supported by axles located between the upper and lower edges ofthe sills, a pair of drop bottom doors swingable longitudinally of the car between the sills, and means mounting the doors on the sills for said swinging movement, said means including a pair of spaced pivot axes on the door, a pair of horizontally and vertically spaced pivot axes on the car,'and a plurality of devices connecting said axes whereby said doors may swing longitudinally of the car.

12. In a drop bottom mine car, a body having side sills supported by axles located between the upper and lower edges of the sills, a pair of drop bottom doors swingable longitudinally of the car between the sills, an upper and a lower pivotal axis for each door carried by the car above and y below the plane of the door, a pair of pivotal axes carried by each door, and a plurality of links connecting said axes whereby said doors may swing longitudinally of the car.

13. In a drop bottom car, the combination of a bottom door normally retaining lading in the car and swingable to an open position for discharge of lading, and pairs of links pivotally connected to the door and car at points spaced longitudinally in the direction of door swing to control the swinging thereof, said links oscillating in opposite directions relative to each other during portions only of their control over the opening door.

14. In a drop bottom car, the combination of a bottom door normally retaining lading in the car and swingable to an open position for discharge of the lading, and pairs of oscillating links pivotally connected to the door and to the car at points spaced longitudinally of the door in its direction of swing, said links reversing their References Cited in the le of this patent UNITED STATES PATENTS Name Date Shields June 26, 1951 Number 

